Analog Devices Inc./Maxim Integrated MAX6301CSA+

Overview

MAX6301CSA+ from Maxim Integrated is an adjustable low-power microprocessor supervisory circuit with active-low open-drain reset output, 4µA supply current, 1.22V internal reference, and externally programmable reset/watchdog timeout via capacitors on SRT/SWT pins. It monitors VCC or external voltages in battery-powered embedded controllers requiring brownout immunity and watchdog supervision.

For engineers reviewing the MAX6301CSA+ datasheet, MAX6301CSA+ pinout, MAX6301CSA+ application, or MAX6301CSA+ equivalent, key selection criteria include its guaranteed RESET assertion down to VCC = 1V, 500× watchdog timeout multiplier via WDS pin, power-supply transient immunity up to 100mV/50µs, and compatibility with manual reset and wake-up timer implementations.

Technical Context

The MAX6301CSA+ implements a precision bandgap reference (1.22V ±25mV) feeding a high-impedance comparator monitoring RESET IN, with timing controlled by 500nA current sources at SRT and SWT pins. Its reset logic asserts active-low RESET for a user-defined period after threshold violation, while the watchdog timer clears on WDI or WDS transitions and supports normal (ms-range) or extended (up to 22-minute) timeout modes.

Reset assertion is guaranteed for VCC ≥ 1V; the open-drain output requires an external pullup. The WDS pin selects watchdog mode-ground for normal timeout (e.g., 4ms with 1500pF), VCC for 500× extension (e.g., 2s with same capacitor)-and resets the timer on state change. Power-supply transient immunity is achieved via internal hysteresis and propagation delay filtering.

Key Specifications

Pinout & Package

MAX6301CSA+ is housed in an 8-pin SO (Small Outline) package per JEDEC MS-012, with 1.27mm pitch and RoHS-compliant lead-free finish (indicated by '+' suffix).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar microprocessor supervisory applications.

Compared with MAX6303CSA+, the MAX6301CSA+ offers lower system-level component count via open-drain output but requires a pullup; versus TPS3808G01DBVR, it trades ultra-low current for full configurability in brownout and watchdog behavior-critical for portable and industrial firmware resilience.

Availability

MAX6301CSA+ is available at Aetrix Electronics and suitable for medical portable monitors, industrial embedded controllers, smart energy meters, set-top box power management, and battery-powered instrumentation requiring stable component supply across extended production lifecycles.

Supply support for MAX6301CSA+ includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Maxim Integrated (now part of Analog Devices) designs precision analog and mixed-signal ICs for power, sensing, and interface applications in industrial, medical, and communications systems.

The MAX6301–MAX6304 family was engineered specifically for low-power microprocessor supervision in space-constrained, battery-operated, and noise-immune embedded systems-emphasizing adjustability, reliability, and minimal quiescent current.

FAQ

What is the minimum VCC required for MAX6301CSA+ to assert RESET?

The MAX6301CSA+ guarantees RESET assertion for VCC ≥ 1V. Below this voltage, output drive capability degrades, but the device remains functional down to VCC = 0V with appropriate external pulldown. This ensures robust startup behavior in battery-powered systems experiencing gradual voltage decay, and is verified across the 0°C to +70°C commercial temperature range specified for the MAX6301CSA+.

How do I configure the reset threshold voltage for MAX6301CSA+?

Connect an external resistor divider between VCC and GND, with the midpoint tied to RESET IN (Pin 1). Use VRST = 1.22 × (R1 + R2)/R2, where R2 is typically 1MΩ and R1 is calculated for the desired threshold. For example, to set VRST = 3.0V, R1 = 1.46MΩ. The MAX6301CSA+ internal reference and comparator ensure accuracy independent of VCC variation.

Can the watchdog function be disabled on MAX6301CSA+?

Yes - in extended mode (WDS = VCC), the watchdog can be disabled by leaving WDI unconnected or three-stating its driver. The MAX6301CSA+ internally pulses WDI near timeout expiration to prevent reset. In normal mode (WDS = GND), WDI must be actively toggled; leaving it floating is not permitted and will cause unintended resets.

What capacitor types are recommended for SRT and SWT on MAX6301CSA+?

Ceramic capacitors with leakage <10nA are mandatory for SRT and SWT pins, as the MAX6301CSA+ uses precision 500nA current sources to charge them. X7R or C0G dielectrics are preferred. Avoid electrolytic or high-leakage film types, which distort timeout periods. Typical values range from 100pF (100µs timeout) to 10nF (27ms timeout), per t = 2.67 × C (pF) in µs.

Does MAX6301CSA+ support monitoring voltages other than VCC?

Yes - the MAX6301CSA+ RESET IN pin accepts any DC voltage source, enabling supervision of auxiliary rails (e.g., 1.8V core, 2.5V analog). Simply connect the target rail through the same resistor divider formula used for VCC. Layout best practices apply: keep RESET IN traces short and away from noisy signals to preserve high-impedance accuracy.